The Garden Bridge is a planned 366m long footbridge that would cross the River Thames between Waterloo Bridge and Blackfriars Bridge. The bridge will carry an expansive garden, featuring trees, shrubs and plants, together with many paved footpaths and pedestrian areas.
Structurally, the bridge design consists of a series of radial and circumferential steel trusses originating at the two main river piers. These trusses are enclosed by an upper ‘soil’ deck and a lower copper-nickel soffit shell of complex geometry which will give the bridge an elegant and unique appearance.
Rendel was appointed as a member of the Bouygues Travaux Publics/Cimolai JV as the lead checking engineer for Category III design check. The check covers the main bridge and foundations but also covers the works association with moving the HQS Wellington (mooring dolphins and river wall works).
Rendel’s services included independent checking, centred with the production of a global 3D model of the bridge in LUSAS. This model aimed to capture the complex geometry and topology of the bridge with the truss members modelled as beam elements, and the soffit modelled with shell elements. The model also captured the construction sequence of the bridge, which aims to achieve ‘zero’ bending moment at the river piers on completion by using a combination of ballast and prestress.